1. Field of the Invention
The present invention relates to a motor-operated flow control valve suitable for use in internal combustion engines, and more particularly to an exhaust gas recirculation control valve for internal combustion engines.
2. Description of the Related Art
Conventional motor-operated flow control valves have such a known structure that a rotor unit of a motor for driving a valve is rotatably supported by a pair of ball bearings disposed in upper and lower portions of the rotor unit.
Those conventional motor-operated flow control valves are disclosed in, for example, U.S. Pat. Nos. 4,432,318, 4,381,747, 4,378,767, 4,378,768, 4,414,942, 4,397,275 and U.S. Pat. No. 5,184,593, JP-A-7-190227 and 7-190226, etc.